Field
The disclosure relates to a method of manufacturing a semiconductor device, and a semiconductor device.
Related Art
A semiconductor device having a trench-type insulated structure has been known conventionally (as described in, for example, JP H06-224437A, JP 2001-267570A and JP 2009-117593A). In the methods disclosed in JP H06-224437A, JP 2001-267570A and JP 2009-117593A, a p-type semiconductor region is provided in the vicinity of the outer periphery of a bottom face of a trench by ion implantation, with a view to suppressing the potential crowding in the vicinity of the outer periphery of the bottom face of the trench.
In some semiconductors such as a gallium nitride (GaN)-based semiconductor, however, there may be a difficulty in forming the p-type semiconductor region by ion implantation. The ion implantation may be likely to arise a defect of crystal in the semiconductor, and such a defect may be unlikely to be recovered by heat treatment. There is accordingly a need for a technique that suppresses the potential crowding in the vicinity of the outer periphery of a bottom face of a trench without ion implantation of a p-type impurity.